Rivcst.e00 (100 km buffer from the ice-free coastline and sea navigable
waterways) is an ARC/INFO interchange file. The file can only be used
with Geographic Information System (GIS) software, such as ARC/INFO, the
file's native format, or by importing it into another GIS software package.

Rivcst.e00 was calculated in Plate Caree equidistant cylindrical
projection. Distance was measured from the coast or a sea-navigable
waterway, excluding coastline in the Arctic and sub-Arctic regions above
the winter extent of sea-ice and the rivers that flow to it. The source
of winter sea-ice extent is: NGS (National Geographic Society). 1995.
/The World: Political/ (map). Washington, D.C. The source of the digital
coastline is: ESRI (Environmental Systems Research Institute) 1996.
/ArcWorld Supplement Data Reference and User's Guide/. Redlands,
California. Rivers categorized as navigable in the ArcAtlas (ESRI, 1996)
database are pared down according to three rules using information taken
from Rand McNally (1980), Brittanica Online (1998), and Encyclopedia
Encarta (1998): whether a river accommodates vessels with a minimum
draft of approximately 3 meters (anything smaller is not considered
ocean-going); the point at which a navigable river becomes obstructed by
falls, rapids, locks or dams; and whether the river is frozen during
winter. The references for the sources listed above are: Rand McNally
and Co. 1980. /Encyclopedia of World Rivers/, New York: Rand McNally and
Co. Britannica Online. 1998. Http://www.eb.com. /Encyclopedia Encarta/.
Http://encarta.msn.com <http://encarta.msn.com/>.

This GIS data was created as part of The Center for International
Development?s ongoing research into the role of geography in economic
development (see www.cid.harvard.edu/economic.htm)
<http://www.cid.harvard.edu/cidglobal/economic.htm>. It was created
between 1998 and 1999. Please reference CID if you use this data in a
publication.

